This invention relates to the field of compositions for use as shaving assistants to soften hair and lubricate the skin when shaving with blades or razors.
Presently, the most commonly-available form of shaving preparation has been a foam-type shaving assistant, commonly referred to as shaving cream. Generally, such creams are provided in the form of dispensers (e.g., cans) containing a propellant gas and a composition which generates a foam or lather. As it is not practical to produce such dispensers for small amounts of shaving cream, these cans usually are of substantial size. As a consequence, the cans are not particularly convenient for use when travelling. In addition, the use of many conventional propellants (such as hydrocarbons and, in particular, chlorofluorocarbons) is contraindicated for economic and environmental reasons. Therefore, it would be desirable to provide an alternative form of composition for use in developing a suitable lather for shaving purposes.
U.S. Pat. No. 2,366,759 to Thomas et al. describes a brushless shaving preparation which may be prepared in a substantially anhydrous condition. The disclosed compositions comprise a mixture of vegetable oil (e.g., sesame, groundnut or olive) and a waxy ingredient (e.g., spermaceti or ozokerite). An emulsifying agent may be added to impart hydrophilic properties to the preparation.
U.S. Pat. No. 2,143,060 to Dzialoschinsky et al. describes a solid shaving preparation which evolves oxygen, comprising an intimate mixture of a staple oxygen-producing substance, a binder and a water-soluble filler to facilitate access of water to the oxygen-producing substance. A typical preparation comprises magnesium peroxide, gum arabic, sugar of milk, magnesium carbonate and hydrogen peroxide carbamide.
U.S. Pat. No. 2,838,442 to McMaster describes a shaving stick block comprising carboxymethyl cellulose, an alkali metal salt of an alkyl substituted aromatic sulfonic acid and an inorganic binding agent, such as colloidal magnesium aluminum silicate, formulated in combination with talc and a suitable pigment so as to permit easy application to the beard of the user.
U.S. Pat. No. 2,876,161 to Gieschi describes a brushless shave composition in solid stick form which comprises an oil-in-water solid gel. The non-oily acidic aqueous phase includes a normal chain fatty acid having at least 12 carbon atoms in the hydrocarbon chain and which is solid at room temperatures, as well as triethanolamine and a liquid, non-toxic lower alkylene glycol having from 3 to 6 carbon atoms. The oil phase comprises a mineral oil and lanolin.
U.S. Pat. No. 4,381,293 to Michel describes a shaving composition which is solid in form. This composition comprises a water-soluble polyethylene polymer having a molecular weight of 400,000 or less; a suitable tracking agent component, which may be formed by combining a pigment with a fatty acid-based molecule; a preservative component having bacteriocidal and fungicidal activity; a lubricant component, such as magnesium or zinc stearate; and an anti-caking component, such as silica gel.
In spite of the various suggestions provided in the prior art, such as the patents discussed above, there remains a need for a solid shaving aid composition which provides the desired balance of properties necessary for widespread acceptance by consumers.